1. Field of the Invention
The present invention relates to the problem of external flood water leaking into subterranean rooms, such as basements, through cracks which develop in concrete basement walls due to shrinking of the concrete and/or other exterior problems such as backfill stress, improper backfilling, expansion of clay backfills and settling. The cracks can become larger over a period of time and water enter the cracks under hydrostatic pressure. This increases the volume of exterior water which passes through the cracks and floods over the basement floor.
2. State of the Art
Prior attempts to seal a crack on the inside surface of a basement wall have been unsuccessful because, unless the cause of the cracking is corrected, wall movement adjacent the crack will dislodge the patch material, such as cement, caulk or a rigid seal, allowing the crack to leak again. Similar problems apply to attempts to seal a crack on the outside surface of a basement wall, in addition to the labor and mess of excavating the backfill down to the level of the wall crack to expose it for patching. Wall cracks are weakened expansion joints in the wall which cannot be rigidly sealed without re-cracking or re-opening over time to admit increasing volumes of ground water.
It has been proposed to repair cracks in interior basement walls by enclosing them within an elongate water barrier strip to permit the entry of water but to contain and channel it for gravity-flow down between the wall and the floor into an interior perimeter drain.
Reference is made to U.S. Pat. No. 5,974,755 which discloses the attachment of a strip of rigid plastic over the crack by means of screws, with beads of caulk under the edges of the plastic strip to confine the water flow within and under the plastic strip and down between the wall and the floor. This system is unsatisfactory for a number of reasons. The rigid plastic barrier strip must be pieced and sealed in order to cover wall cracks which wander from the vertical direction by any substantial direction. Also, a rigid plastic barrier strip does not slow or meter the flow of water and/or sediment during or after application of the repair patch, which is unsatisfactory in the case of substantial wall cracks. It is undesirable to force screws into a basement wall since it can result in the migration and widening of the original crack. Also a rigid plastic strip cannot flex or stretch with movement of the basement wall sections adjacent an elongate crack and therefore can become cracked or dislodged over time. Moreover, such a plastic strip is relatively thick and raised above the wall surface so that it is very obtrusive and noticeable.
Reference is also made to U.S. Pat. No. 5,845,456 which discloses a method in which a crack in a basement wall is controlled by first excavating the basement floor and forming a sub-floor drain adjacent the wall crack, widening the mouth of the crack, bonding a plastic vapor barrier strip to the wall to enclose the crack, extending the barrier film below the excavated floor and over the footing to a drain conduit, and then covering the barrier film with a rigid fiberglass panel secured to the wall by mechanical fasteners or an adhesive. Such a system is complicated and expensive, due to the required excavation and floor repair, and has the disadvantages discussed supra in connection with the rigid and obtrusive plastic panels of U.S. Pat. No. 5,974,755.
It is also known to install sub-floor wall drainage conduits in original construction sites in order to permit any water which enters through subsequent wall cracks to flow down the wall and enter the conduit between the wall and the floor to a sub-floor drain tile. Reference is made to my U.S. Pat. No. 5,501,044 as illustrative of one such sub-floor wall drainage conduit.
It is an objective of the present invention to provide a simple, efficient, non-obtrusive method for controlling the flow of exterior flood water through cracks in basement walls and for channeling it between the wall and floor for discharge into a sub-floor wall drain tile, preferably via a sub-floor wall drainage conduit of the type illustrated by my aforementioned U.S. Pat. No. 5,501,044.
A novel method for repairing and draining cracks in interior basement walls and for channeling admitted goundwater down into a sub-floor drain. The present method involves applying over the crack area a thin, unobtrusive patch strip which preferably is colored and/or textured to match the appearance of the basement wall. The patch strip comprises a combination of a thin, flexible water-absorbing, water-wicking base layer of a fabric, such as of open celled plastic foam or natural sponge, or a fibrous fabric such as cotton, and a water-barrier top layer such as a thin coating of an elastomeric caulk composition or a combination of a thin barrier film such as of polyethylene overcoated with the thin coating of elastomeric caulk. The caulk composition preferably is colored and/or textured to match the wall, and is feathered or tapered down to the wall surface to make the appearance of the patch strip less conspicuous and less obtrusive.